Land transformation by humans: A review

Below is a scholarly article recently published as the featured science article in the magazine of the Geological Society of America, GSA Today. Near their conclusion, the authors state “Reducing demand is a critical component of the solution, but in itself is not sufficient, given the magnitude of the problem. Technological progress, particularly in the energy field, is essential, but we also think it unwise to bet too heavily on unspecified future breakthroughs. Reducing and eventually reversing population growth needs to be a large part of the solution…

In recent decades, changes that human activities have wrought in Earth’s life support system have worried many people. The human population has doubled in the past 40 years and is projected to increase by the same amount again in the next 40. The expansion of infrastructure and agriculture necessitated by this population growth has quickened the pace of land transformation and degradation. We estimate that humans have modified >50% of Earth’s land surface. The current rate of land transformation, particularly of agricultural land, is unsustainable. We need a lively public discussion of the problems resulting from population pressures and the resulting land degradation.

Introduction

“Global Change” refers to changes that alter the atmosphere and oceans, and hence are experienced globally. It also refers to local changes that are so common as to be, collectively, of global importance; these include changes in climate, in composition of air and water, in biodiversity, and in land use (Vitousek, 1992; Rockström et al., 2009). Herein, we focus on land use (Fig. 1). Vitousek (1992, p. 7) remarks that this may be the “most significant component of global change” for decades to come.

Many changes in land use are a consequence of the increase in human population and the resulting demand for more resources-among them, minerals, soil, and water. This demand now exceeds that which Earth can provide sustainably. The long-term sustainability issue is more serious than, but exacerbated by, climate change.